The orifice flowmeter can be used to measure the flow of liquid, gas, and steam in the pipeline. The standard orifice plate is designed and manufactured according to the national standard GB/T2624-93, and tested according to JJG640-94. No need for real-flow calibration. The standard orifice plate can adopt three pressure methods: corner connection pressure (including ring chamber pressure), flange pressure or D-D/2 pressure. The standard orifice plate is designed, manufactured and verified according to the national standard, without real-flow calibration, with high precision, simple structure, low manufacturing cost, but large pressure loss. Standard orifice plates are widely used in petroleum, chemical, metallurgy, electric power and other industries.Some precautions during installation of orifice flowmeter:1. The opening of the meter should avoid opening the hole in the forming tube. 2. Pay attention to the length of the straight pipe before and after the flowmeter. 3. If there are electromagnetic, mass and other flow meters with grounding requirements, they should be grounded in accordance with the instructions. 4. When welding the pipeline, the grounding wire should avoid the main body of the instrument to prevent ground current from flowing into the ground through the main body of the instrument and damaging the instrument. 5. During the welding process, avoid ground current flowing through the capillary conduits of single-flange and double-flange instruments. 6, argon arc welding or socket welding can be used for medium and high voltage pulse tubes, and argon arc welding or socket welding should be used. Wind-proof measures should be taken when the wind speed is> 2m/s, otherwise the coating line should be used, and the wind speed> 8m/s, wind-proof measures must be taken, otherwise the welding should be stopped. 7. Pay attention to the installation direction of the flow port of the flow meter throttling device. 8. It is strictly forbidden to use stainless steel pressure pipes; it is strictly forbidden to flatten pressure pipes. 9. The installation position of the impulse pipe, air duct and threading pipe of the instrument should avoid future production operations, avoid high-temperature corrosion, and should be firmly fixed; the lowest lead end of the threading pipe from the upper side should be lower than that of the lower lead end Connect the wiring entrance end of the instrument; drip tee should be added to the bottom end of the threading pipe; Y-type or conical explosion-proof sealing joint should be added near the instrument side; the lowest point of the instrument’s main air line should be the condensation (soil) valve. 10. If the copper gasket used in the instrument is not annealed, it should be annealed before use, and pay attention to the allowable temperature, medium and pressure of the gaskets of various materials. 11. In the field instrument junction box, the grounding of different grounding systems cannot be mixed. The shielded wires of all instruments should be connected to the upper and lower shielding layers respectively. It is forbidden to screw them together to connect the upper and lower shields. 12. When the instrument is in a position where it cannot be observed and inspected, please change the position or install the platform. 13. Prohibit joints in the middle of the instrument line and hide records. The joint of the compensation wire should be welded or crimped. 14. Stainless steel welds should be pickled, passivated and neutralized. 15. Instruments and accessories that need to be degreased should be degreased in strict accordance with the specifications. After degreasing, the instruments and accessories should be sealed and stored to prevent secondary pollution during storage and installation. 16. It is strictly forbidden to use stainless steel pipes to directly contact carbon steel. 17. It is strictly forbidden to cut and open the electroplating and aluminum alloy cable trays by electrical or gas welding, and should use similar mechanical cutting and openings, and do not use tooth saws and special hole openers. 18. It is strictly forbidden to cut and open stainless steel pipes by electric or gas welding. Plasma or mechanical cutting or opening should be used. 19. The instrument threading pipe, cabinet, disc, etc. greater than 36V should be grounded. The threading pipe of the grounded instrument should be treated with conductive paste; instrument threading pipe thread buckle below 36V should have at least anti-rust treatment; the exposed thread buckle should not be more than one thread buckle . 20. Electrical continuity should be maintained in the instrument conduit in the explosion-hazardous area. 21． Volt uses a 250V shaker to measure wire insulation resistance and measure ≥5MΩ. 22. The aluminum alloy bridge should be short-circuited when short-circuited. The galvanized bridge should be tightened with no less than two anti-loosening screws. The length should be reliably grounded within 30 meters. If it exceeds 30 meters, a grounding point should be added every 30 meters. 23. When the instrument cables or instrument cables of different grounding systems share the same slot with the power cord, they are separated by a metal partition. 24. It is strictly forbidden to use gas welding in the installation and processing of instrument panels, cabinets, cabinets and workbenches. The welding method should not be used for installation and fixing. The opening should be opened mechanically. 25. The blind end of the heating and return water instrument should not exceed 100mm. 26. The lower part of the transmitter drain valve should be equipped with a cover to prevent valve leakage (especially in explosion-proof areas). 27. The instrument and its threading pipe and pressure pipe are fixed at one end of the thermal expansion zone (such as a tower, the accessories move with the thermal expansion of the tower), and one end is fixed in the non-thermal expansion zone. Area (such as labor protection room). When connecting the instrument, it should be based on the actual situation on site. Flexible pipes, threading pipes and pressure pipes must have a certain thermal expansion margin. 28. Tower bridges and threading pipes should be set with thermal expansion expansion joints or flexible connections according to the actual situation on site.
The above are the matters needing attention during the installation of the orifice flowmeter. According to the above suggestions, the normal operation of the flowmeter can be ensured. Orifice flowmeter is an important tool for developing industrial and agricultural production, saving energy, improving product quality, and improving economic efficiency and management level. It occupies an important position in the national economy.
Post time: 21-09-21